The evacuation zones on these maps were developed by the Oregon Department of Geology and Mineral Industries in consultation with local officials. Evacuation routes were developed by local officials and reviewed by the Oregon Department of Emergency Management. Note that the tsunami inundation limits shown on these maps represent the worst case scenario for the two types of tsunami shown. The inundation limits are intended only to guide tsunami evacuation for these two extreme events. These maps should not be used for land-use planning or engineering purposes.

A tsunami is a series of sea waves usually caused by a displacement of the ocean floor by an undersea earthquake. As tsunamis enter shallow water near land, they increase in height and can cause great loss of life and property damage.

Recent research suggests that tsunamis have struck the Oregon coast on a regular basis. They can occur any time, day or night. Typical wave heights from tsunamis occurring in the Pacific over the last 80 years have been 20–45 feet at the shoreline. A few waves however have been much higher—as much as 100 feet or more—because of local conditions.

We distinguish between a tsunami caused by an undersea earthquake near the Oregon coast (LOCAL TSUNAMI) and an undersea earthquake far away from the coast (DISTANT TSUNAMI).

A LOCAL TSUNAMI could come onshore within 15 to 20 minutes after the earthquake—before there is time for official warning from a national warning system. Ground-shaking from the earthquake may be the only warning you have. Evacuate quickly!

A distant tsunami will take four hours or more to come onshore. You will feel no earthquake, and the tsunami will generally be smaller than that from a local earthquake. There will typically be time for an official warning and evacuation to safety.

Some communities will signal the need for evacuation for a distant tsunami by a sounding a STEADY 3-MINUTE SIREN BLAST.

All coastal communities will receive announcements over NOAA weather radio that the local area has been put into an official TSUNAMI WARNING.

In isolated areas along beaches and bays you may not hear a warning. Here, a sudden change of sea level should prompt you to move immediately inland to high ground.

If you hear the 3-minute blast or see sudden sea level changes, evacuate away from shoreline areas, then turn on your local broadcast media or NOAA weather radio for further information.

FOR BOTH DISTANT AND LOCAL TSUNAMIS:

Evacuate on foot if at all possible because of potential traffic jams.

Stay away from potentially hazardous areas until you receive an ALL CLEAR from local officials. Dangerous waves can persist for several hours, and local officials must inspect all flooded or earthquake-damaged structures before anyone can go back into them.

If you need help evacuating, tie something WHITE (sheet or towel) to the front door knob. Make it large enough to be visible from the street. If the emergency is a distant tsunami, then help may arrive. In the event of a local earthquake and tsunami, it is unlikely that anyone will help you, so make a plan and be prepared!

After evacuation, check with the local area commander if you can help with special skills or need assistance with locating lost family.